Coloring forgery prevention structure and coloring forgery prevention medium

ABSTRACT

A forgery prevention structure configured by layering at least a relief forming layer, a first reflection layer, a functional thin film layer, and a second reflection layer, in this order, wherein the relief forming layer has, on one side, a relief structure which has an effect of diffracting, scattering, absorbing, and polarizing/separating at least a part of a wave-length range of visible light; the first reflection layer and the functional thin film layer are provided along a whole surface of an uneven area of the relief structure; the second reflection layer is provided in an arbitrary area which covers a part of the uneven area of the relief structure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2011-116827, filed on May 25, 2011; theentire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a colored forgery prevention structureand a colored forgery prevention medium which exhibit a high forgeryprevention effect and a high alteration prevention effect.

A forgery prevention structure is used to prevent forgery of valuablepapers, brand-name products, certificates, and personal authenticationmedia, and functions to prove articles to be genuine.

In recent years, a forgery prevention structure using an optical elementsuch as a diffraction grating or a hologram is applied to variousarticles because a special optical effect thereof can be distinguishedat a glance. A lot of optical elements include a micro structure, suchas a diffraction grating, a hologram, or a lens array. These microstructures are difficult to analyze. In addition, an optical elementincluding a micro structure is manufactured using an electron-beamlithography apparatus, and can therefore exhibit an excellent forgeryprevention effect.

However, a hologram which has a silver metallic luster has been widelymarketed for a packaging purpose and an amusement purpose. Therefore,the security thereof is deteriorating. To respond to thesecircumstances, for example, Patent Literature 1 proposes a hologramwhich partially comprises a reflection layer, as a hologram whichprovides a forgery prevention effect. The hologram which includes areflection layer having a micro pattern is considered difficult tocounterfeit.

On the other hand, a proposal has been made for a hologram which has ametallic luster in a vivid color tone other than silver. For example,Patent Literature 1 proposes a hologram structure with which a desiredcolor tone is obtained and which is excellent in design and/or security.Color tones can be more or less chosen by using this method. However,the reflectance of a high-intensity ink layer is lower than that of avapor-deposited film of aluminum and has a tendency to scatter.Therefore, there is a defect that a colored metallic luster, e.g., ametal luster of a vivid color tone such as gold or copper is notobtained.

Further, a partially colored reflection layer is difficult to provide ona hologram through the method according to Patent Literature 1. Thisdefect is caused by the difficulty in overprinting a reflection layer ofa high-luminance ink in an identical pattern over a colored layer withhigh positional accuracy, after pattern-printing of the colored layer.

Another method has been considered in which a vivid color reflectionlayer is formed of gold or copper by a vacuum deposition method or asputtering method, and patterned by etching. However, forming aprecious-metal reflection layer by etching requires high costs andexhibits low productivity.

CITATION LIST Patent Literature

Patent Literature 1: Jpn. Pat. Appln. KOKAI Publication No. 2008-162260

BRIEF SUMMARY OF THE INVENTION

An object of the invention is to provide a forgery prevention structurewhich is excellent in design and/or security.

According to the first aspect of the invention, there is provided aforgery prevention structure configured by layering a first reflectionlayer, a functional thin film layer, a second reflection layer, and aprotection layer, in this order, characterized in that:

the relief forming layer has, on one side, a relief structure which hasan effect of diffracting, scattering, absorbing, andpolarizing/separating at least a part of a wave-length range of visiblelight;

the first reflection layer and the functional thin film layer areprovided along a whole surface of an uneven area of the reliefstructure;

the second reflection layer is provided in an arbitrary area whichcovers a part of an uneven area of the relief structure;

the protection layer is provided so as to cover only an area of thesecond reflection layer; and

three layers of the first reflection layer, the functional thin filmlayer, and the second reflection layer cause at least a partial range ofvisible light to interfere.

According to the second aspect of the invention, there is provided aforgery prevention structure configured by layering a first reflectionlayer, a functional thin film layer, a second reflection layer, and aprotection layer, in this order, characterized in that:

the relief forming layer has, on one side, a relief structure includinga first relief and a second relief which performs an effect ofdiffracting, scattering, absorbing, and polarizing/separating awavelength range of at least a part of visible light;

the surface of the first relief has a smaller uneven surface area incomparison with the surface of the second relief;

the first reflection layer and the above functional thin film layer areprovided along a whole surface of an uneven area of the reliefstructure; and

the second reflection layer and the protection layer are provided so asto cover only a surface of the functional thin film layer of the firstrelief; and

three layers of the first reflection layer, the functional thin filmlayer, and the second reflection layer cause at least a partial range ofvisible light to interfere.

According to the third aspect of the invention, there is provided theforgery prevention structure according to claim 1 or 2, characterized inthat the first reflection layer includes at least one selected from agroup of tantalum oxide, niobium oxide, titanium oxide, indium oxidetin, zirconium oxide, cerium oxide, and hafnium oxide, in the first orsecond aspect.

According to the fourth aspect of the invention, there is provided aforgery prevention structure characterized by forming the firstreflection layer of a high-intensity transparent reflection paint whichis made of high refraction particles, in any one of the first to thirdaspects.

According to the fifth aspect of the invention, there is provided aforgery prevention structure characterized in that the relief structureincludes at least one of a diffraction structure, a hologram, aconvergence lens array, a diffusion lens array, and a scatteringstructure at least partially on an identical plane, in any one of thefirst to fourth aspects.

According to the sixth aspect of the invention, there is provided aforgery prevention structure layered at least on the substrate, and theforgery prevention structure is characterized by being a stickerconfiguration which layers a relief forming layer, a first reflectionlayer, a functional thin film layer, a second reflection layer, aprotection layer, and an adhesion layer, in this order on the substrate,in any one of the first to five aspects.

According to the seventh aspect of the invention, there is provided aforgery prevention structure layered at least on the substrate, and theprevention structure is characterized by being a sticker transfer foilconfiguration which layers a relief forming layer, a first reflectionlayer, a functional thin film layer, a second reflection layer, aprotection layer, and an adhesion layer, in this order on the substrate,and which can be separated from the substrate, in any one of the firstto five aspects.

In the foregoing seventh and eighth aspects, a separation protectionlayer may be provided between the substrate and the relief forminglayer, if needed. The separation protection layer is to achieve smoothand stable separation from the substrate, and a material having anexcellent mold-release characteristic relative to the substrate may beselected.

According to the eighth aspect of the invention, there is provided aforgery prevention medium to which the forgery prevention structure inany one of the first to seventh aspects is adhered.

According to the invention, a forgery prevention structure can beprovided which is excellent in design and/or security.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention, andtogether with the general description given above and the detaileddescription of the embodiments given below, serve to explain theprinciples of the invention.

FIG. 1 is a sectional view showing a forgery prevention structureaccording to the first embodiment;

FIG. 2A is a sectional view showing a process of manufacturing a forgeryprevention structure according to the first embodiment;

FIG. 2B is a sectional view showing a process of manufacturing a forgeryprevention structure according to the first embodiment;

FIG. 2C is a sectional view showing a process of manufacturing a forgeryprevention structure according to the first embodiment;

FIG. 3 is a sectional view showing another example of the forgeryprevention structure according to the first embodiment;

FIG. 4 is a sectional view showing still another example of the forgeryprevention structure according to the first embodiment;

FIG. 5 is a sectional view showing a forgery prevention structureaccording to the second embodiment;

FIG. 6 is a sectional view showing a process of manufacturing a forgeryprevention structure according to the second embodiment;

FIG. 7A is a sectional view showing a process of manufacturing a forgeryprevention structure according to Comparative Example 1; and

FIG. 7B is a sectional view showing a process of manufacturing theforgery prevention structure according to the Comparative Example 1.

DETAILED DESCRIPTION OF THE INVENTION First Embodiment

Hereinafter, a forgery prevention structure according to the firstembodiment of the invention will be described with reference to thedrawings. FIG. 1 is a sectional view showing the forgery preventionstructure according to the first embodiment.

The forgery prevention structure 1 comprises a relief forming layer 2, afirst reflection layer 3, a functional thin film layer 4, a secondreflection layer 5, and a protection layer 6 which are layered in thisorder. The relief forming layer 2 has, on one side, a relief structure 7having a micro uneven pattern. The relief structure 7 has an effect ofdiffracting, scattering, absorbing, and polarizing/separating at least apart of a wave-length range of visible light. The first reflection layer3 and the functional thin film layer 4 are provided along a wholesurface of an uneven area of the relief structure 7. In an arbitraryarea (first area) 8 of the relief structure 7, the second reflectionlayer 5 is provided covering a part of an uneven area of the reliefstructure 7. The protection layer 6 is provided so as to cover only thesecond reflection layer 5.

In the first area 8, the first reflection layer 3, the functional thinfilm layer 4, the second reflection layer 5, and the protection layer 6are layered in this order, and a colored reflection layer is obtainedwhich makes three layers of the first reflection layer 3, the functionalthin film layer 4, and the second reflection layer 5 cause interferencein at least a partial range of visible light. The three layers allow arelief structure to be designed to be capable of forming a reflectionlayer which causes a color tone to change in accordance with view anglesand has a vivid color reflection layer.

The colored reflection layer exists only in the part of the first area8, and only the patterned second reflection layer 5 is colored. In thefirst area 8, the patterned second reflection layer 5 is colored initself. As a result, the second reflection layer 5 is a colored patternin itself, and therefore, the coloring ink is patterned and printed.Accordingly, it is possible to avoid positional misalignment which maybe caused between a colored pattern and a reflection layer 5 byemploying a conventional method of forming the reflection layer to bealigned with the colored pattern.

The second area 9 includes neither the second reflection layer 5 nor theprotection layer 6 but is formed of the first reflection layer 3 and thefunctional thin film layer 4. Therefore, also in the second area 9, acolorless optical effect owing to a relief structure can be obtained.

A typical theory concerning a three-layer interference film is describedin Jpn. Pat. Appln. KOKAI Publication No. 2010-175812. This patentpublication describes a multi-layer interference film including three ormore layers. In contrast, the forgery prevention structure according tothe first embodiment is limited to a three-layer interference film. Thatis, there is an advantage that reflection of the interference color canbe enhanced as the total number of reflection layers increases. However,in this case, there is a problem that coloring occurs because at leasttwo reflection layers exist also in the second area where the reflectionlayer of the top layer does not exist. That is, in a multi-layer film offive or more layers, similar interference colors appear in a part (firstarea) including a high diffraction reflection layer in an uppermostlayer and a part (second area) not including the same. Therefore, if amulti-layer film of five or more layers is applied to the forgeryprevention structure according to the first embodiment, the first area 8and the second area 9 tend to have similar color tones.

In the forgery prevention structure according to the first embodiment,the part (first area 8) including the second reflection layer 5 iscolored by interference while the part (second area 9) not including thesecond reflection layer 5 causes no interference and becomes colorless.Accordingly, sufficient difference in color tone can appear between thefirst area 8 and the second area 9.

Therefore, the forgery prevention structure according to the firstembodiment can exhibit a high forgery prevention effect by the coloredreflection relief structure in the first area 8 and by the colorlessreflection relief in the second area 9.

Next, a method of manufacturing a forgery prevention structure accordingto the first embodiment will be described with reference to FIG. 2A toFIG. 2C.

First Process

As shown in FIG. 2A, a relief forming layer 2 is formed on the wholesurface of a substrate 11. The relief forming layer 2 can be formed bycoating, e.g., by wet coating on the substrate 11. In addition, thesubstrate itself may serve as a relief forming layer.

Subsequently, an original relief plate made of metal or resin and havingan uneven shape is prepared. The uneven shape of the original reliefplate is transferred to a surface of the relief forming layer 2, to forma relief structure 7 having an uneven surface in the relief forminglayer 2 (see the same FIG. 2A).

The method of transfer may be a well-known method such as a pressmethod, a casting method, or a photopolymer method, or a hybrid methodwhich combines any of these methods.

Second Process

As shown in FIG. 2B, a first reflection layer 3, a functional thin filmlayer 4, and a thin film layer 12 for a second reflection layer areformed in this order on a surface of the relief structure 7.

The first reflection layer 3 and the functional thin film layer 4 can beformed by well-known wet coating or dry coating. The thin film layer 12for the second reflection layer can be formed by dry coating,preferably.

Third Process

A protection layer 6 which functions as an etching mask is formed on thethin film layer 12 for the second reflection layer. Subsequently, thethin film layer 12 for the second reflection layers is selectivelyremoved by etching with an etching treatment agent, with the protectionlayer 6 used as a mask, to form the second reflection layer 5. That is,the thin film layer 12 for the second reflection layer is left to remainin an area under an area (first area 8) of the protection layer 6, asthe second reflection film 5. The thin film layer 12 for the secondreflection layer is removed from under the other areas (second area 9).Here, the first reflection layer 3 need not be removed by etching.

Specifically, the thin film layer 12 for the second reflection layer isformed on the whole surface of the functional thin film layer 4, andthereafter, a protection layer 6 is formed on the thin film layer 12 forthe second reflection layer by a well-known wet printing method.Thereafter, the thin film layer 12 for the second reflection layer isselectively subjected to etching with the protection layer 6 used as anetching mask, to form a patterned second reflection layer 5.

The forgery prevention structure according to the first embodiment ismanufactured through the first to third processes above, but is notlimited thereto.

Next, more detailed descriptions will be made of materials, requiredcharacteristics, and specific manufacturing methods of layers formingthe forgery prevention structure according to the first embodiment.

Substrate

The substrate used in the manufacturing method described above ispreferably a film substrate. As the film substrate, a material which isless deformed or degraded by heat, pressure, and electromagnetic waveswhich are applied during formation of a micro uneven pattern (reliefstructure) is used. A film made of plastic, such as PET (polyethyleneterephthalate), PEN (polyethylene naphthalate), or PP (polypropylene),may be used for the film substrate. Depending on necessity, a paper madeof multiple plastic layers or a paper impregnated with resin may be usedas a substrate.

Relief Forming Layer

On a surface of the relief forming layer, a relief structure which has amicro uneven pattern is preferably copied sequentially a great number oftimes. As a typical method, the “press method” described in U.S. Pat.No. 4,194,073, the “casting method” described in Utility ModelRegistration No. 2524092, or the “photopolymer method” described in U.S.Pat. No. 4,088,884 can be employed.

Particularly in the “photopolymer method” (2P method: a photosensitiveresin method), radiation-cured resin is poured between a relief die (diefor copying a micro uneven pattern) and a flat substrate (plastic film),and hardened by radiation. Thereafter, the hardened film is separatedtogether with the substrate from the die for duplication. The reliefstructure which has a high-definition micro uneven pattern can beobtained by this method. The relief structure obtained by this methodprovides a micro uneven pattern with a higher forming accuracy than the“pressing method” and the “cast method” which use thermoplastic resin,and is excellent in heat resistance or chemical resistance.

Further, as a method of preparing a relief forming layer having a novelrelief structure, there is a method of molding with use of an opticalcuring resin which is solid or highly viscous at a normal temperature ora method of adding a mold release material.

Used as a material for the relief forming layer can be, for example:thermoplastic resin, such as acrylic-based resin, epoxy-based resin,cellulose-based resin, or vinyl-based resin; urethane resin of acrylicpolyol or polyester polyol with a reactive hydroxyl group, added andbridged with polyisocyanate as a crosslinking agent; or theremosettingresin, such as a melamine-based resin, epoxy resin, or phenol-basedresin or a compound thereof. Any other material than described can beused as long as a micro uneven pattern can be formed of the material.

Used as a material of the relief forming layer applicable to thephotopolymer method described above can be, for example, a monomer, anoligomer, or a polymer, which has an ethylene unsaturated bond or anethylene unsaturated group. Used as the monomer can be, for example,1,6-hexane diol, neopentylglycol diacrylate, trimethylolpropanetriacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate,dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate. Theoligomer may be, for example, epoxy acrylate, urethane acrylate, orpolyester acrylate. As the polymer, for example, urethane denaturationacrylic resin and epoxy denaturation acrylic resin can be used.

As a material of the relief forming layer using optical cationicpolymerization can be used, for example, a monomer containing an epoxygroup, an oligomer, a polymer, a compound containing an oxetaneskeleton, or vinyl ethers can be used. When the ionizing radiationcuring resin described above is hardened with light such as ultravioletrays, a photo polymerization initiator can be added. Depending on thetypes of resin, an optical radical polymerization initiator, an opticalcationic polymerization initiator, or a combination thereof (hybridtype) can be selected.

In addition, it is possible to use a mixture of a monomer, an oligomer,and a polymer, each of which has an ethylene unsaturated bond or anethylene unsaturated group, to provide the mixture of these componentswith a reactive group in advance and to crosslink each other by anisocyanate compound, a silane coupling agent, an organic titanatecrosslinker, an organic zirconium crosslinker, or an organic aluminate,and to provide the bridged components with a reactive group in advanceand to bridge still another resin skeleton by an isocyanate compound, asilane coupling agent, an organic titanate crosslinker, an organiczirconium crosslinker, or organic aluminate. According to the method asdescribed above, a polymer can be obtained which exists in solid form ata normal temperature, has good fabricability because of its lower tact,and leaves little dirt on an original plate, with use of polymer havingan ethylene unsaturated bond or an ethylene unsaturated group.

Used as the optical radical polymerization initiator described above canbe, for example: benzoin, or benzoin methyl ether, a benzoin-basedcompound, such as benzoin ethyl ether or anthraquinone, ananthraquinone-based compound, such as methyl anthraquinone oracetophenone; a phenyl-ketone-based compound, such as diethoxyacetophenone, benzophenone, hydroxy acetophenone, 1-hydroxy cyclohexylphenyl ketone, alpha-amino acetophenone,2-methyl-1-(4-methylthiophenyl)-2-morpholino-propane-1-ON, benzyl methylketal, thioxanthone, acyl phosphine oxide, or Michler's ketone.

Used as the optical cationic polymerization initiator in the case ofusing the compound described above capable of optical cationicpolymerization can be, for example, an aromatic diazonium salt, anaromatic iodonium salt, an aromatic sulfonium salt, an aromaticphosphonium salt, or a mixed ligand metal salt. In the case of aso-called hybrid material which uses both optical radical polymerizationand optical cationic polymerization, polymerization initiators of bothpolymerizations can be used in a mixture. In addition, it is possible touse an aromatic iodonium salt or an aromatic sulfonium salt, which canstart both polymerizations with one type of initiator.

In a resin composite including a radiation-cured resin and a photopolymerization initiator, a mixing rate of the photo polymerizationinitiator may be appropriately selected although 0.1 to 15 mass % isused in general. The resin composite may be used together with asensitizing dye in combination with a photo polymerization initiator.According to necessity, the resin composite may also include a dye, apigment, various additives (a polymerization inhibitor, a levelingagent, an antifoaming agent, an anti-sagging agent, an adhesionimprovement agent, a coated surface modifier, a plasticizer, a compoundcontaining nitrogen), and a crosslinking agent (for example, epoxyresin). In addition, a non-reactive resin (including thermoplastic resinor thermosetting resin described above) may be added to improvefabricability.

In the manufacturing method described above, a material for a reliefforming layer may be selected, in consideration of fluidity to someextent which allows molding, and considering that thermostability andchemical resistance desired by a coated film can be obtained aftermolding.

In a process of forming a relief forming layer, a coating method may beused. In that case, the material for a relief forming layer may becoated on the substrate. In particular, wet coating allows formation atlow costs. A material diluted with a solvent may be coated and dried inthe course of forming a relief forming layer, to adjust thickness.

The thickness of the relief forming layer is preferably set within, forexample, a range of 0.1 to 10 μm. Though depending on the method ofmanufacturing the relief forming layer as described above, too great athickness causes protrusions and wrinkles of resin due to the pressureduring processing for transferring a relief structure. On the otherhand, if too thin, fluidity at the time of transferring the reliefstructure may be insufficient to achieve molding. Though transferproperties of the micro uneven pattern change depending on the shape ofthe pattern, the thickness of the relief forming layer is preferably 1to 10 times, or more preferably 3 to 5 times a desired depth ofunevenness.

After the relief forming layer is brought into contact with an originalrelief plate having a desired relief structure, the shape of theoriginal relief plate is transferred to one side of the relief forminglayer by using heat, pressure, or microwaves. The relief structure maybe formed not only on one side but also two sides, i.e., front and backsurfaces of the relief forming layer.

A well-known method may be used as the method of manufacturing theoriginal relief plate to be used. A rolled original plate allowscontinuous molding.

First Reflection Layer

The first reflection layer functions to reflect electromagnetic waves.In the case of reflecting light which has penetrated the relief forminglayer and the relief structure with a micro uneven pattern, a higherrefractive-index material than the refractive index of the substrate orthe relief forming layer is used. In this case, the difference inrefractive index between the first reflection layer and the reliefforming layer is preferably 0.2 or more. By setting the difference inrefractive index to be 0.2 or more, refraction and reflection occur atthe interface between the relief forming layer and the first reflectionlayer. In addition, the first reflection layer which covers the reliefstructure may emphasize an optical effect created by the micro unevenstructure.

Metal materials, such as Al, Sn, Cr, Ni, Cu, Au, and Ag, can be usedsingularly or in the form of a compound thereof, as a material for thefirst reflection layer.

The first reflection layer preferably has a transmittance of 40% orless. An interference color is generated by the three-layer interferencefilm made of the first reflection layer, the functional thin film, andthe second reflection layer. Therefore, the first reflection layerpreferably has transparency and also preferably has a diffractivedifference of 0.2 or more relative to the relief forming layer and thefunctional thin film layer, to cause reflection at both interfaces.

The first reflection layer which has such transparency can be realizedby forming a thin film made of one or a compound of the metal materialsdescribed above.

Examples of materials other than described above, each of which can beused for the transparent first reflection layer, are cited below.Numerals in parentheses each indicate a refractive index n. Ceramicswhich can be used are, for example: Sb₂O₃ (3.0), Fe₂O₃ (2.7), TiO₂(2.6), CdS (2.6), CeO₂ (2.3), ZnS (2.3), PbCl₂ (2.3), CdO (2.2), Sb₂O₃(5.0), WO₃ (5.0), SiO (5.0), Si₂O₃ (2.5), In₂O₃ (2.0), PbO (2.6), Ta₂O₃(2.4), ZnO (2.1), ZrO₂ (5.0), MgO (1.0), SiO₂ (1.45), Si₂O₂ (10), MgF₂(4.0), CeF₃ (1.0), CaF₂ (1.3-1.4), AlF₃ (1.0), Al₂O₃ (1.0), and GaO(2.0). Organic polymers which can be used are, for example, polyethylene(1.51), polypropylene (1.49), polytetrafluoroethylene (1.35), polymethylmethacrylate (1.49), and polystyrene (1.60).

The first reflection layer needs resistance against an etching treatmentagent used to perform a pattern processing on the second reflectionlayer in the manufacturing method described above. For example, thereflectance of the first reflection layer in a second area needs not tochange due to dissolution, corrosion, deterioration, or separation butneeds to be stable. Therefore, the first reflection layer may beappropriately selected from the materials described above. Depending onthe case, a plurality of materials may be used.

Resistance against the etching treatment agent of the first reflectionlayer in the second area may be strengthened by the functional thin filmlayer arranged so as to cover the first reflection layer. That is, evenif the first reflection layer has low resistance against the etchingtreatment agent, the reflection function of the first reflection layerin the second area can be prevented from deterioration by protecting thefirst reflection layer from the etching treatment agent bymulti-layering with the functional thin film layer.

Since the first reflection layer is formed as a thin film with a uniformthickness on the micro uneven surface of the relief forming layer in themanufacturing method described above, a dry coating method, such as avacuum deposition method, a sputtering method, or a CVD method, ispreferably employed.

For the first reflection layer, it is possible to use a high-luminanceoptical reflection ink, an organic polymer, or fine particles of theorganic polymer, which is obtained by dispersing micro powder, sol, ormetal nano particles of the metals described above, ceramics, or anorganic polymer. This first reflection layer can be formed by awell-known printing method, such as a gravure printing method, a flexoprinting method, or a screen printing method. To provide the firstreflection layer by such a printing method as described, adjustment maybe performed so as to set the dried film thickness to 0.001 to 10 μm orso.

Functional Thin Film Layer

The functional thin film layer comprises a function to allow light,which has penetrated the substrate, the relief forming layer having amicro uneven pattern, and the first reflection layer, to furtherpenetrate. Further, the functional thin film is a middle layer in thethree-layer interference film since an interference color is caused bythe three-layer interference film made of the first reflection layer,the functional thin film layer, and the second reflection layer. Ingeneral, the three-layer interference film is configured by a layeredstructure made of a high-refraction layer, a low-refraction layer, and ahigh-refraction layer. Therefore, the functional thin film as the middlelayer preferably has a refractive index which is lower by 0.2 or morethan refractive indices of the first and second reflection layers. Bysetting the difference in refractive index to be 0.2 or more, refractionand reflection can be caused at the interface between the relief forminglayer and the first reflection layer.

In the second area, two layers of the first reflection layer and thefunctional thin film are layered. Therefore, an interference color isnot obtained.

The functional thin film layer is the middle layer in the three-layerinterference film made of the first reflection layer, the functionalthin film layer, and the second reflection layer, and is thereforepreferably a low-refraction film with a high transparency. Specifically,the functional thin film layer has a refractive index equal to or lowerthan the first reflection layer, and can cause reflection on bothinterfaces.

Examples of materials which can be used for the transparent functionalthin film layer are cited below. Numerals in parentheses each indicate arefraction index n. Ceramics which can be used are, for example: Sb₂O₃(3.0), Fe₂O₃ (2.7), TiO₂ (2.6), CdS (2.6), CeO₂ (2.3), ZnS (2.3), PbCl₂(2.3), CdO (2.2), Sb₂O₃ (5.0), WO₃ (5.0), SiO (5.0), Si₂O₃ (2.5), In₂O₃(2.0), PbO (2.6), Ta₂O₃ (2.4), ZnO (2.1), ZrO₂ (5.0), MgO (1.0), SiO₂(1.45), Si₂O₂ (10), MgF₂ (4.0), CeF₃ (1.0), CaF₂ (1.3-1.4), AlF₃ (1.0),Al₂O₃ (1.0), and GaO₂ (2.0). Organic polymers which can be used are, forexample, polyethylene (1.51), polypropylene (1.49),polytetrafluoroethylene (1.35), polymethyl methacrylate (1.49), andpolystyrene (1.60).

The functional thin film layer is the middle layer of the three-layerinterference film, and functions as a layer for adjusting an opticalpath difference, which controls an interference color. Therefore, thefunctional thin film can be formed to be thin with a uniform thicknessalong the micro uneven surface of the relief forming layer. Therefore, agaseous phase method (dry coating method), such as a vacuum depositionmethod, a sputtering method, or a CVD method, is preferably employed toform the functional thin film.

Second Reflection Layer

The second reflection layer is provided along the relief structure, andreflects light which has penetrated the relief forming layer, the firstreflection layer, and the functional thin film layer. For the secondreflection layer, a material having a higher refractive index than thatof the functional thin film is used. In this case, the difference inrefractive index between both layers is preferably 0.2 or more. Bysetting the difference in refractive index to be 0.2 or more, refractionand reflection can be caused at the interface between the functionalthin film and the second reflection layer.

For example, metal materials, such as Al, Sn, Cr, Ni, Cu, Au, and Ag,can be used in sole or in form of a compound thereof, as a material forthe second reflection layer.

Examples of other materials than the metals and chemical compoundsdescribed above, which can be used for the transparent second reflectionlayer, are cited below. Numerals in parentheses each indicate arefraction index n. Ceramics which can be used are, for example: Sb₂O₃(3.0), Fe₂O₃ (2.7), TiO₂ (2.6), CdS (2.6), CeO₂ (2.3), ZnS (2.3), PbCl₂(2.3), CdO (2.2), Sb₂O₃ (5.0), WO₃ (5.0), SiO (5.0), Si₂O₃ (2.5), In₂O₃(2.0), PbO (2.6), Ta₂O₃ (2.4), ZnO (2.1), ZrO₂ (5.0), MgO (1.0), SiO₂(1.45), Si₂O₂ (10), MgF₂ (4.0), CeF₃ (1.0), CaF₂ (1.3-1.4), AlF₃ (1.0),Al₂O₃ (1.0), and GaO₂ (2.0). Organic polymers which can be used are, forexample, polyethylene (1.51), polypropylene (1.49),polytetrafluoroethylene (1.35), polymethyl methacrylate (1.49), andpolystyrene (1.60).

The second reflection layer may be appropriately selected among theforegoing materials in consideration of patterning by changing areflectance or a transparency through dissolution, corrosion, ordeterioration with an etching treatment agent, in accordance with themanufacturing method described above. Depending on the case, a pluralityof materials may be used. When patterning the second reflection layer,it is preferable to select appropriately a material and a process whichdo not degrade the reflection effect of the first reflection layer.

A method of performing a wet etching treatment on the second reflectionlayer made of any of the metals or metal oxides described above can beadopted as a method of changing a reflectance or a transparency of thesecond reflection layer by dissolution. Well-known acids, alkalis,organic solvents, oxidizing agents, and reducing agents can be used foretching. Depending on materials of the second reflection layer, a dryetching method may be used. Also in such a patterning process of thesecond reflection layer as described above, only the second reflectionlayer is patterned, and the first reflection layer does not change.

As a method of changing the reflectance or transparency of the secondreflection layer, for example, it is possible to employ a method ofoxidizing a second reflection layer made of copper, by an oxidizingagent, to be changed into copper oxide, or a method of oxidizing asecond reflection layer made of aluminum, by an oxidizing agent, to bechanged into boehmite. Also in such a patterning process of the secondreflection layer as described above, only the second reflection layer ispatterned, and the first reflection layer does not change.

Apart from the method of changing a dissolution characteristic and adeterioration characteristic of the second reflection layer, it is alsopossible to change optical characteristics, such as a refractive index,a reflectance, or a transmittance, or a practical durability, such asweather resistance or interlayer tightness.

The second reflection layer is formed as a thin film with a uniform filmthickness on a micro uneven surface of a relief forming layer in themanufacturing method described above. A dry coating method, such as avacuum deposition method, a sputtering method, or a CVD method ispreferably employed.

Protection Layer

The protection layer is light-transmissive and functions as a mask layerwhen forming the second reflection layer by patterning.

A material which has resistance to an etching treatment agent whenetching the second reflection layer may be used for the material of theprotection layer, and may be provided with such a film thickness thatcan ensure resistance. For example, when the protection layer is formedby wet coating such as printing, for example, thermoplastic resin,thermosetting resin, moisture curing resin, ultraviolet curing resin, orelectron-beam curing resin can be used. Specifically, acrylic resin,polyester resin, or polyamide imide resin can be used. Further, alubricant, e.g., wax such as polyethylene powder or carnaba wax may beadded. The lubricant can be added up to a quantity of 20 parts by weightto an extent of not being clouded. Such resin can be diluted with asolvent to an adequate viscosity and can then be applied to wet coating.On the other hand, when the protection layer is formed by dry coating,e.g., a transparent inorganic material such as silica or alumina can beused. Photosensitive resin can be used as a material other than thosedescribed above.

The protection layer of the forgery prevention structure shown in FIG. 1is preferably formed by the wet coating described above.

As a method of forming a pattern for the second reflection layer using aprotection layer, a method of forming a pattern by changing thereflectance or transparency of the second reflection layer bydissolution, corrosion, or deterioration, as described above, can beemployed.

Typically, wet etching or dry etching is assumed, and in such a patternforming method as described above, a protection layer may be formed in apatterned part of the second reflection layer in a part to remain.

In the above, layers which form the forgery prevention structureaccording to the first embodiment have been described specifically.However, a reflection film may be provided on the outermost surface inorder to improve optical characteristics. The surface protection film orreflection film can be provided by using a well-known coating method.

In order to improve interlayer sealing tightness, a corona treatment, aframe treatment, a plasma treatment, and primer painting may beperformed. In order to improve optical characteristics, anantireflection treatment may be performed on the outermost layer.

To further improve the design, a multilayer interference film may beformed by coloring a layer or by configuring the reflection layer in amultilayer configuration.

Next, a modification of the forgery prevention structure according tothe first embodiment will now be described with reference to FIG. 3 andFIG. 4. The same members as in FIG. 1 described above will be denoted atthe same reference signs, and descriptions thereof will be omittedherefrom.

FIG. 3 is a sectional view showing a forgery prevention sticker. Theforgery prevention structure 21 comprises a substrate 22, a reliefforming layer 2, a first reflection layer 3, a functional thin filmlayer 4, a second reflection layer 5, a protection layer 6, and anadhesion layer 23, which are layered in this order.

The forgery cancellation sticker 21 configured as described above isused when transferring the relief forming layer 2, the first reflectionlayer 3, the functional thin film layer 4, the second reflection layer5, and the protection layer 6 to another substrate (transfer target),and the adhesion layer 23 is used for adhesion to yet another substrate.After transfer, the substrate 21 may be separated.

By using such a forgery prevention sticker 21 as described above, aforgery prevention medium to which the forgery prevention structure isadhered can be obtained.

FIG. 4 is a sectional view showing a forgery prevention transfer foil. Aforgery prevention transfer foil 31 has a structure in which a separablesubstrate 32, a relief forming layer 2, a first reflection layer 3, afunctional thin film layer 4, a second reflection layer 5, a protectionlayer 6, and an adhesion layer 33 are layered in this order.

By pressing a heat medium such as a heat roll or a heat plate to thesubstrate 32 and by heating the medium to a transfer temperature, theadhesion layer of the forgery prevention transfer foil 31 is pressed incontact with another substrate as a transfer target. Simultaneously, thesubstrate 32 is separated at the interface between the substrate 32 andthe relief forming layer 2.

By using such a forgery prevention transfer foil 31 as described above,the forgery prevention medium in which the forgery prevention structureis adhered to the transfer target can be obtained.

In the foregoing forgery prevention structures in FIG. 3 and FIG. 4, aseparation protection layer may be provided between the substrate andthe relief forming layer, if needed. The separation protection layer isfor achieving a smooth and stable separation from the substrate.Therefore, the separation protection layer is made of a material with agood mold-release characteristic relative to the substrate.

The substrate used for the forgery prevention sticker and forgeryprevention transfer foil is preferably a film substrate, as describedabove. As the film substrate, a material which is less deformed ordegraded by heat, pressure, and electromagnetic waves, which are appliedduring formation of a micro uneven pattern (relief structure), is used.A film made of plastic, such as PET (polyethylene terephthalate), PEN(polyethylenenaphthalate), or PP (polypropylene), may be used for thefilm substrate. Depending on the need, a paper made of multiple plasticlayers or a paper impregnated with resin may be used as a substrate.

Second Embodiment

FIG. 5 is a sectional view showing a forgery prevention structureaccording to the second embodiment.

A forgery prevention structure 41 comprises a relief forming layer 42, afirst reflection layer 43, a functional thin film layer 44, a secondreflection layer 45, and a protection layer 46, which are layered inthis order. One side of the relief forming layer 42 has a reliefstructure comprising a first relief 47 and a second relief 48 with amicro uneven pattern which performs an effect of diffracting,scattering, absorbing, and polarizing/separating a wavelength range ofat least a part of visible light. The surface of the first relief 47 hasa smaller uneven surface area in comparison with the surface of thesecond relief 48. That is, the first relief 47 has gentle concave andconvex parts, and there are wide intervals between the concave andconvex parts. On the other hand, the second relief 48 has a shape withsteeper concave and convex parts in comparison with the first relief 47,and intervals between the concave and convex parts are smaller incomparison with the first relief 47.

The first reflection layer 43 and the functional thin film layer 44 areprovided along the micro uneven surface of the relief structure 7 (thefirst and second reliefs 47 and 48). The second reflection layer 45 andthe protection layer 46 are provided so as to cover only the surface ofthe functional thin film layer 44 of the first relief 47.

That is, in the first area 49, the first reflection layer 43, thefunctional thin film layer 44, the second reflection layer 45, and theprotection layer 46 are layered in this order on the uneven surface ofthe relief forming layer 42. A colored reflection layer is obtainedwhich causes at least a partial range of visible light to interfere,through three layers of the first reflection layer 43, the functionalthin film layer 44, and the second reflection layer 45. The three layersallow a relief structure to be designed to be capable of forming areflection layer which causes a color tone to change in accordance withthe angle of view and a vivid-color reflection layer.

The colored reflection layer exists only in the first area 49, and onlythe patterned second reflection layer 45 is colored. In the first area49, the patterned second reflection layer 45 is colored in itself. As aresult, the second reflection layer 45 is a colored pattern in itself,and therefore, a coloring ink is patterned and printed. Accordingly, itis possible to avoid positional misalignment between a colored patternand a reflection layer in the conventional method of forming thereflection layer in alignment with the colored pattern.

The second area 50 is an area where only the first reflection layer 43and the functional thin film layer 44 are layered on the micro unevensurface of the second relief 48 of the relief forming layer 42 and whereneither the second reflection layer 45 nor the protection layer 46exist. Therefore, also in the second area 50, a colorless optical effectowing to a relief structure can be obtained.

In addition, the first area 49 and the second area 50 have differentrelief structures (the first area 49: the first relief 47, the secondarea 50: the second relief 48, and the uneven surface area: the firstrelief 47 surface <the second relief 48 surface). For example, bothstructures are reliefs of diffraction gratings and therefore havedifferent uneven surface areas. Accordingly, both structures exhibitdifferent color change effects.

Further, in the forgery prevention structure 41, a boundary between thefirst area 49 and the second area 50 is a boundary between differentrelief structures. Therefore, there is no positional misalignment amongthe pattern of the second reflection layer 45, the colored pattern, andthe pattern (first relief 47) of the relief structure of the first area49.

Therefore, in the forgery prevention structure according to the secondembodiment, a more precise and complex optical effect can achieve a highforgery prevention effect by the colored reflection relief structure inthe first area 49, the colorless reflection relief structure in thesecond area 50, or different color change effects between the secondareas 40 and 50. A much higher forgery prevention effect can beexhibited.

Next, a method of manufacturing a forgery prevention structure accordingto the second embodiment will be described.

First Process

A relief forming layer is formed on the whole surface of a substrate.The relief forming layer can be formed by coating, e.g., by wet coatingon the substrate. In addition, the substrate may serve as a reliefforming layer in itself.

Next, an original relief plate made of a metal or resin and having anuneven shape is prepared. The uneven shape of the original relief plateis transferred to a surface of the relief forming layer, to form arelief structure comprising first and second reliefs having an unevensurface in the relief forming layer. The surface of the first relief hasa smaller uneven surface area in comparison with the surface of thesecond relief. That is, intervals between concave and convex parts ofthe first relief are wider than those of the second relief.

The method of transferring the shape may be a well-known methoddescribed in the first embodiment, such as a press method, a castingmethod, or a photopolymer method, or a hybrid method which combinesthese methods.

Second Process

On the surface of the relief structure of the reflection forming layer,a first reflection layer, a functional thin film layer, and a thin filmlayer for a second reflection layer are formed in this order.

The first reflection layer and the functional thin film layer can beformed by well-known wet coating or dry coating. The thin film layer forthe second reflection layer can be formed by dry coating, preferably.

Third Process

A protection layer which functions as an etching mask is formed on thethin film layer for the second reflection layer. Subsequently, the thinfilm layer for the second reflection layer is selectively removed byetching with an etching treatment agent, with the protection layer usedas a mask, to form the second reflection layer. That is, the thin filmlayer for the second reflection layer is left to remain in an area underthe area (first area 49) of the protection layer, to form the secondreflection film 5. The thin film layer for the second reflection layeris removed from under the other areas (second area 50). Here, the firstreflection layer need not be removed by etching.

The forgery prevention structure according to the second embodiment ismanufactured through the first to third processes described above,though is not limited thereto.

The patterned protection layer and second reflection film can be formedby another method, as follows. This method will now be described withreference to FIG. 6. After forming a thin film layer 51 for a secondreflection layer on the whole surface of a functional thin film layer 44by a gaseous phase method, such as a vacuum deposition method or asputtering method, a protection layer 46 is formed on the whole surfacealso by a gaseous phase method, such as a vacuum deposition method or asputtering method. At this time, a relief structure of a relief forminglayer 42 comprises a first relief 47 and a second relief 48 having ashorter interval between concave and convex parts than the relief 47, asshown in FIG. 6. Therefore, the thin film layer 51 for the secondreflection layer and the protection layer 46 are formed with asufficient thickness in the first area 49, and are formed thinly only attip ends of convex parts of the uneven shape in the second area 50 wherethe second relief 48 is present. Therefore, when a subsequent etchingtreatment is performed on the whole surface, the protection layer 46 andthe thin film layer 51 for the second reflection layer which are formedthinly only at tip ends of convex parts of the uneven shape in thesecond area 50 are removed by etching preferentially. The thin filmlayer 51 for the second reflection layer (which functions as the secondreflection layer 45) and the protection layer 46 remain only in thefirst area 49, thereby forming a pattern.

A transparent inorganic material such as silica or alumina is used as amaterial of the protection layer 46 described above.

According to the method as described above, the second reflection layer45 (and protection layer 46) can be formed on the first relief (firstarea) in accordance with shapes of the preset first and second reliefs47 and 48. Therefore, coloring can be effected only in the first area,and optical effects of different reliefs in the first and second areascan be obtained.

Materials and required characteristics of individual layers forming theforgery prevention structure according to the second embodiment are thesame as those described in the first embodiment.

Alternatively, the forgery prevention structure according to the secondembodiment may be modified as shown in FIG. 3 (forgery preventionsticker) and FIG. 4 (forgery prevention transfer foil). By using such aforgery prevention sticker or a forgery prevention transfer foil, aforgery prevention medium to which the forgery prevention structure isadhered can be obtained.

Hereinafter, Examples of the invention will be described.

EXAMPLE 1

Example 1 will be described with reference to a configuration of FIG. 3as a typical example. An ink made of a composite described below wasapplied to a substrate 11 made of a 25-μm-thick transparent polyethyleneterephthalate (PET) film to obtain a film thickness of 2 μm afterdrying. The ink was then dried to form the relief forming layer 2.Subsequently, a relief pattern of a diffraction grating was formed onthe surface of the relief forming layer 2 by a roll embossing method. Afirst reflection layer 3 having a film thickness of 50 nm was formedalong the relief pattern by performing vacuum deposition of titaniumoxide (TiO2) to the relief forming layer 2. Further, a functional thinfilm layer 4 having a 130 nm film thickness was formed on the firstreflection layer 3 by performing vacuum deposition of silica (SiO2).Subsequently, an aluminum layer having a film thickness of 50 nm wasformed on the functional thin film layer 4 by performing vacuumdeposition of aluminum. Subsequently, an ink made of a compositedescribed below was printed on the aluminum layer to form a protectionlayer 6 having a star pattern. The thickness of the protection layer 6was 1 μm as a dry film thickness. Thereafter, a second reflection layer5 having a star pattern was formed by etching an aluminum layer partwhich was exposed by performing an alkaline etching treatment with theprotection layer 6 used as an etching mask. Thereafter, an ink made of acomposite described below was printed on the functional thin film 4including the protection layer 6 by a gravure printing method, and wasdried to form an adhesion layer 23 having a film thickness of 3 μm, toobtain a forgery prevention sticker 21.

Relief forming-layer ink composite” Acrylic resin 20.0 weight partMethyl ethyl ketone 50.0 weight part Ethyl acetate 30.0 weight part“Protection layer ink composite” Polyamide resin 20.0 weight partEthanol 50.0 weight part Toluene 30.0 weight part “Adhesion layer inkcomposite” Acrylics adhesive   50 weight part Silica   10 weight partMethyl ethyl ketone   40 weight part

COMPARATIVE EXAMPLE 1

As shown in FIG. 7A, an ink made of a composite described below wasprinted on a substrate 101, to form a colored layer 102 having a starpattern. Subsequently, a relief forming layer 103 was formed on thesubstrate 101 including the colored layer 102 by the same method as inExample 1. The relief structure 104 which had micro unevenness on oneside of the relief forming layer 103 was formed. Subsequently, analuminum layer having a film thickness of 50 nm was formed on the reliefforming layer 103 by performing vacuum deposition of aluminum.Subsequently, a protection layer ink composite which is the same as thatin Example 1 was printed on the aluminum layer, to form a protectionlayer 105 having a star pattern. The thickness of the protection layer105 was 1 μm as a dry film thickness. Subsequently, a second reflectionlayer 106 was formed by etching an aluminum layer part which was exposedby performing an alkaline etching treatment with the protection layer105 used as an etching mask (see FIG. 7B). Thereafter, the same adhesionlayer ink composite as in Example 1 was printed on the functionalforming layer including the protection layer by a gravure printingmethod, and was dried to form an adhesion layer having a film thicknessof 3 μm, to thereby obtain a forgery prevention sticker.

Between the colored layer of the star pattern and the protection layerof the star pattern, matching was performed as much as possible byoverprinting (overlay registration printing).

“Pattern colored layer ink composite” Urethane printing ink/yellow 50.0weight parts Methyl ethyl ketone 25.0 weight parts Ethyl acetate 25.0weight parts

Forgery prevention was evaluated for the forgery prevention stickersaccording to Example 1 and Comparative Example 1.

Evaluation of Forgery Prevention Characteristics

After taking an enlarged photograph by a microscope, an area ratio wasevaluated between the “colored reflection layer area and the “reflectionlayer area (the area of the second reflection layer in Example 1 and thearea of the reflection layer in Comparative Example 1)” (coloredreflection layer area mm²/reflection layer area mm² (the area of thesecond reflection layer in Example 1 and the area of the reflectionlayer in Comparative Example 1)). After taking an enlarged photograph bya microscope, photograph image analysis was conducted, and a positionalmisalignment width (mm) between the “area of the colored reflectionlayer” and the “area of the second reflection layer” was measured.

The area ratio (mm²/mm²) and the positional misalignment width (mm) eachwere measured at 20 portions, and averaged values and maximum valueswere obtained for the ratio and width.

The following table 1 shows results thereof.

TABLE 1 Comparative Example 1 Example 1 Area ratio of colored 1.00 1.00layer/reflection layer. Averaged values (n = 20) Area ratio of colored1.00 1.02 layer/reflection layer. Maximum values (n = 20) Positionalmisalignment 0.00 mm 0.76 mm between colored layer & reflection layer.Averaged values (n = 20) Positional misalignment 0.00 mm 1.00 mm betweencolored layer & reflection layer. Maximum values (n = 20)

As is apparent from Table 1, the forgery prevention structure accordingto Example 1 achieves an excellent area ratio of 1.00 and positionalmisalignment of 0.00 mm (less than 0.01 mm below the limit ofmeasurement). In contrast, the forgery prevention structure according toComparative Example 1 achieves an area ratio of 1.02 and causespositional misalignment of 1.00 mm at maximum.

Through visual observation of the forgery prevention structure accordingto Comparative Example 1, misalignment of the coloring layer relative toa reflection layer was checked.

INDUSTRIAL APPLICABILITY

According to the present invention, a forgery prevention structure withhigh design quality and high security can be provided with a reflectionlayer of a desired color tone and an arbitrary pattern, and a forgeryprevention structure which is excellent in design and/or security can beprovided. Hence, applications to valuable papers, brand-name products,certificates, and personal authentication media are available.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

1. A forgery prevention structure configured by layering at least arelief forming layer, a first reflection layer, a functional thin filmlayer, a second reflection layer, and a protection layer, in this order,characterized in that: the relief forming layer has, on one side, arelief structure which has an effect of diffracting, scattering,absorbing, and polarizing/separating at least a part of a wave-lengthrange of visible light; the first reflection layer and the functionalthin film layer are provided along a whole surface of an uneven area ofthe relief structure; the second reflection layer is provided in anarbitrary area which covers a part of the uneven area of the reliefstructure; the protection layer is provided so as to cover only an areaof the second reflection layer; and three layers of the first reflectionlayer, the functional thin film layer, and the second reflection layercause at least a partial range of visible light to interfere.
 2. Aforgery prevention structure configured by layering at least a reliefforming layer, a first reflection layer, a functional thin film layer, asecond reflection layer, and a protection layer, in this order,characterized in that: the relief forming layer has, on one side, arelief structure comprising a first relief and a second relief whichperform an effect of diffracting, scattering, absorbing, andpolarizing/separating a wavelength range of at least a part of visiblelight; a surface of the first relief has a greater uneven surface areain comparison with a surface of the second relief; the first reflectionlayer and the functional thin film layer are provided along a wholesurface of an uneven area of the relief structure; the second reflectionlayer and the protection layer are provided so as to cover only asurface of the functional thin film layer of the second relief; andthree layers of the first reflection layer, the functional thin filmlayer, and the second reflection layer cause at least a partial range ofvisible light to interfere.
 3. The forgery prevention structureaccording to claim 1, wherein the first reflection layer includes atleast one selected from a group of tantalum oxide, niobium oxide,titanium oxide, indium oxide tin, zirconium oxide, cerium oxide, andhafnium oxide.
 4. The forgery prevention structure according to claim 2,wherein the first reflection layer includes at least one selected from agroup of tantalum oxide, niobium oxide, titanium oxide, indium oxidetin, zirconium oxide, cerium oxide, and hafnium oxide.
 5. The forgeryprevention structure according to claim 1, wherein the first reflectionlayer is formed by a high-luminance transparent reflection paintingmaterial, which is made of high refraction particles.
 6. The forgeryprevention structure according to claim 2, wherein the first reflectionlayer is formed by a high-luminance transparent reflection paintingmaterial, which is made of high refraction particles.
 7. The forgeryprevention structure according to claim 1, wherein a stickerconfiguration in which the relief forming layer, the first reflectionlayer, the functional thin film, the second reflection layer, theprotection layer, and an adhesion layer are layered in this order on asubstrate at least.
 8. The forgery prevention structure according toclaim 1, wherein at least a substrate is provided, at least the reliefforming layer, the first reflection layer, the functional thin film, thesecond reflection layer, the protection layer, and an adhesion layer arelayered in this order on the substrate, and the layers as an object havea transfer foil configuration which can be separated from the substrate.9. A forgery prevention medium to which the forgery prevention mediumaccording to claim 7 is adhered.
 10. A forgery prevention medium towhich the forgery prevention medium according to claim 8 is adhered. 11.The forgery prevention structure according to claim 2, wherein a stickerconfiguration in which the relief forming layer, the first reflectionlayer, the functional thin film, the second reflection layer, theprotection layer, and an adhesion layer are layered in this order on asubstrate at least.
 12. The forgery prevention structure according toclaim 3, wherein a sticker configuration in which the relief forminglayer, the first reflection layer, the functional thin film, the secondreflection layer, the protection layer, and an adhesion layer arelayered in this order on a substrate at least.
 13. The forgeryprevention structure according to claim 4, wherein a stickerconfiguration in which the relief forming layer, the first reflectionlayer, the functional thin film, the second reflection layer, theprotection layer, and an adhesion layer are layered in this order on asubstrate at least.
 14. The forgery prevention structure according toclaim 5, wherein a sticker configuration in which the relief forminglayer, the first reflection layer, the functional thin film, the secondreflection layer, the protection layer, and an adhesion layer arelayered in this order on a substrate at least.
 15. The forgeryprevention structure according to claim 6, wherein a stickerconfiguration in which the relief forming layer, the first reflectionlayer, the functional thin film, the second reflection layer, theprotection layer, and an adhesion layer are layered in this order on asubstrate at least.
 16. The forgery prevention structure according toclaim 2, wherein at least a substrate is provided, at least the reliefforming layer, the first reflection layer, the functional thin film, thesecond reflection layer, the protection layer, and an adhesion layer arelayered in this order on the substrate, and the layers as an object havea transfer foil configuration which can be separated from the substrate.17. The forgery prevention structure according to claim 3, wherein atleast a substrate is provided, at least the relief forming layer, thefirst reflection layer, the functional thin film, the second reflectionlayer, the protection layer, and an adhesion layer are layered in thisorder on the substrate, and the layers as an object have a transfer foilconfiguration which can be separated from the substrate.
 18. The forgeryprevention structure according to claim 4, wherein at least a substrateis provided, at least the relief forming layer, the first reflectionlayer, the functional thin film, the second reflection layer, theprotection layer, and an adhesion layer are layered in this order on thesubstrate, and the layers as an object have a transfer foilconfiguration which can be separated from the substrate.
 19. The forgeryprevention structure according to claim 5, wherein at least a substrateis provided, at least the relief forming layer, the first reflectionlayer, the functional thin film, the second reflection layer, theprotection layer, and an adhesion layer are layered in this order on thesubstrate, and the layers as an object have a transfer foilconfiguration which can be separated from the substrate.
 20. The forgeryprevention structure according to claim 6, wherein at least a substrateis provided, at least the relief forming layer, the first reflectionlayer, the functional thin film, the second reflection layer, theprotection layer, and an adhesion layer are layered in this order on thesubstrate, and the layers as an object have a transfer foilconfiguration which can be separated from the substrate.